Fluid Mechanics and Hydraulic Machinery Miscellaneous
 A phenomenon is modeled usingn dimensional variables with k primary dimensions. The number of nondimensional variables is

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NA
Correct Option: C
NA
 The parameters which determines the friction factor for turbulent flow in a rough pipe are

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NA
Correct Option: C
NA
 A test is conducted on a onefifth scale model of a Francis turbine under a head of 2 m and volumetric flow rate of 1 m^{3}/s at 450 rpm. Take the water density and the acceleration due to gravity as 10^{3} kg/m^{3} and 10 m/s^{2}, respectively. Assume no losses both in model and prototype turbines. The power (in MW) of a full sized turbine while working under a head of 30 m is _______ (correct to two decimal places).

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D_{m} = 1 D_{p} 5
Model: H = 2 m, Q = 1 m^{3} /s
Prototype: H = 30 m, P =?
N = 450 rpm, ρ = 1000 kg/m^{3} /g = 10 m/s^{2}
For model, pm = ρgQH = 1000 × 10 × 1 × 2 = 20 kW
= 29045.24 kW
= 29.05 mWCorrect Option: C
D_{m} = 1 D_{p} 5
Model: H = 2 m, Q = 1 m^{3} /s
Prototype: H = 30 m, P =?
N = 450 rpm, ρ = 1000 kg/m^{3} /g = 10 m/s^{2}
For model, pm = ρgQH = 1000 × 10 × 1 × 2 = 20 kW
= 29045.24 kW
= 29.05 mW
 For a Pelton wheel with a given water jet velocity, the maximum output power from the Pelton wheel is obtained when the ratio of the bucket speed to the water jet speed is ______ (correct to two decimal places).

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In pelton wheel:
η= 2(vu u^{2}) v^{2}
where,
u = bucket speed
v = water jet speed
So, For maximum efficiency:dx = 0 du
2(v – 2u) = 0 v = 2uu = v 2 Correct Option: A
In pelton wheel:
η= 2(vu u^{2}) v^{2}
where,
u = bucket speed
v = water jet speed
So, For maximum efficiency:dx = 0 du
2(v – 2u) = 0 v = 2uu = v 2
 Which one of the following statements is TRUE?

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Kaplan turbine is an axialflow reaction turbine
Correct Option: D
Kaplan turbine is an axialflow reaction turbine